Grating



March 13, 1962' G. G. GREULICH 3,024,712

GRATING Filed Oct. 4, 1957 FGJ.

INVENTOR GERALD G. GREULICH ATTORNEY;

United States Patent 3,024,712 GRATING Gerald G. Greulich, FortLauderdale, Fla., assignor, by mesne assignments, to Kerrigan Iron WorksCompany, Nashville, Tenn., a corporation of Tennessee Filed Oct. 4,1957, Ser. No. 688,263 4 Claims. (Cl. 94-30) This invention relates toload carrying metallic structures and more particularly to load carryingopen metallic gratings, such as commonly used for walkways, manholecovers, platforms, stair treads, catwalks, sidewalks, runways forvehicles, bridge floors and the like.

Heretofore, such gratings have been made by piercing some of thecomponents and lacing other components through the pierced holes. Otherconstructions embody spacer members placed between parallel loadcarrying members, such spacer members being riveted or welded to theload carrying members. One particular arrangement illustrating the useof spacer members embodies dovetail faces on the spacer memberscorresponding to dovetail grooves in the sides of the load carryingmembers. In constructing a grating from such members, it is necessary toinsert the spacer members at the ends of the load carrying members andthen move them along the length thereof to the proper locations. Afterall of the spacer members have been properly located, deformations areformed to prevent longitudinal movement.

Still other gratings are assembled by placing reticulated or alternatelybent members ,between adjacent straight load carrying members, with theassembly fastened into a rigid unit by bolts, rivets or welds at thepoints of contact or engagement. Sometimes, such structure may embodynotching or interlocking crossed-over members and often the crossed barsare weld-forged into surfaces or edges of the load carrying members.Still another method of constructing `a grating of the type describedinvolves the formation of suitable longitudinal Sections, as byextruding or the like, and subsequently piercing the upper portions soas to allow the passage of air and the like through the openings. Manyforms of gratings have also been made by means of casting molten metalin molds of the nal shape of grating desired. Expanded metal is alsoutilized to a considerable extent for certain grating applications.

The present invention is more particularly concerned with improvementsin gratings made up of individual sections to a desired size. Inaccordance with the principles of the present invention, assembly of theindividual sections into a rigid unit is accomplished without thenecessity of welding or other analogous procedures and without thenecessity of piercing t-he metal sections so as to remove substantialportions thereof and thereby reduce its strength.

In general, the present invention utilizes an arrangement of opposedflanges on one element of the assembly and spaced faces or portions ont-he adjacent element arranged to enter between the flanges. One of theflanges is undercutpto receive one of the faces, while the other flangeis straight so as to permit each pair of adjacent elements of thegrating to be assembled without the necessity of a longitudinal slidingmovement throughout their length, but rather by a simple lateral andarcuate relative movement between the two. The elements may be readilylocked into their assembled position by deforming the straight `flangeover the other face.

Accordingly, it is an object of the present invention to provide amethod of assembling a grating of the type described which effects asaving in the time and effort heretofore required to effect assembly ofprior art gratings.

Still another object of the present invention is the provision of agrating assembly of the type described having individual elements of theassembly.

Still another object of the present invention is the provision of agrating of the type described, which is pleasing in appearance, sturdyin construction and economical to assemble.

These and other objects of the present invention will become moreapparent during the course of the following detailed description andappended claims.

The invention may best be understood with reference to the accompanyingdrawings wherein `an illustrative ernbodiment is shown.

In the drawings:

lFIGURE l is a fragmentary top plan view of a grating embodying theprinciples of the present invention;

FIGURE 2 is an enlarged cross-sectional view taken along the line 2 2 ofFIGURE 1;

'FIGURE 3 is a fragmentary perspective view of a portion of the grating;and

FIGURES 4 and 5 are vertical cross-sectional views illustrating themanner in which adjacent bars of the grating are assembled.

Referring now more particularly to the drawings, there is shown inFIGURE 1 a grating assembled in accordance with the principles of thepresent invention. The grating includes a plurality of straight loadbearing members or bearer bars 10 and reticulated connector bars ormembers 12 secured between adjacent bearer bars to maintain the same inspaced parallel relation.

Preferably, the reticulated connector bars 12 are bent to provide aplurality of longitudinally extending bearer bar engaging portions 14interconnected by transversely extending diagonal portions 16.`Alternate bearer bar engaging portions 14 are disposed in the samegeneral plane and successive bearer bar engaging portions are spacedapart laterally.

Grating assemblies of alternate straight bars maintained in parallelrelation by reticulated connector bars are known. The present inventionis more particularly concerned with a novel method of assembling suchbars and a novel structure for rigidly securing the same in assembledposition. In general, the securing means of the present inventionembodies the provision on one of the bars of a straight flange and aspaced opposed undercut flange. The adjacent bar or member has spacedportions thereon engageable between Ithe opposed flanges by relativelateral and arcuate movements between the adjacent bars so as toinitially insert one of the portions within the undercut flange andsubsequently move that portion and the undercut flange into registeringengagement and the opposite portion and the straight flange intocontact. In this initial position of assembly, the bars are readilyretained together and may be readily locked into rigid engagement bydeforming the straight flange, as by bending or the like, over the otherportion.

With the above in mind, the structure illustrated in the drawings toexemplify one embodiment of the principles outlined above will now bedescribed. Both the bearer bars 10. and the connector bars 12 arepreferably initially constructed so that they have a uniformcross-sectional configuration throughout their longitudinal extent. Itis preferable to utilize extruded aluminum, although it will be readilyunderstood that other materials may be utilized which are either rolled,extruded or otherwise fabricated. Each bearer bar is generally I-shapedin cross-section and includes a central web 18 having a pair of flanges20 on its upper end extending from opposite sides thereof and a pair offlanges 22 on its lower end extending from the opposite sides thereof.Each of the upper flanges 20 includes a lower connector bar engagingsurface 24 which is undercut so that the lowermost point along a lineformed by the intersection of a transverse plane therewith is disposedon the outer end portion of the flange and all points along such lineinwardly of the lowermost point are disposed thereabove. As shown, thelower connector bar engaging surface 24 of each flange 20 constitutes aflat dovetail face which is disposed at an angle between approximately30 and 40 with respect to the horizontal.

Each lower flange 22 constitutes a straight flange having an upperconnector bar engaging surface 26 arranged so that no points along aline formed by the intersection of a transverse plane therewith aredisposed above a horizontal plane touching any point along the lineadjacent the inner end portion of the flange. As shown, the flanges 22have the usual configuration of a conventional l-beam. ln addition tothe flanges 20 and 22, each bearer bar has its upper surface providedwith a series of ridges 28, which serves not only to enhance theappearance of the grating, but also to improve its anti-slipcharacteristics.

Each connector bar 12 is preferably also of general I-shapedconfiguration in cross-section and includes a central web 30 having apair of upper flange engaging portions 32 on the upper end thereofextending from opposite sides thereof and a pair of lower flangeengaging portions 34 on the lower end thereof extending from oppositesides thereof. Each of the upper portions 32 constitutes a flangeextending outwardly from the web 30 of the connector bar and includes anupper bearer bar engaging surface 36 arranged to engage the lowersurface 24 of an adjacent upper flan-ge 20 of an adjacent bearer bar.Preferably, the outer end of each flange portion 32 terminates in avertical surface 38 arranged to be parallel to and to be almost or inactual contact with the web of an adjacent bearer bar adjacent theassociated flange surface 24. Preferably, the web 30 has an extension 40disposed above the portions 32 and provided with a single ridged uppersurface 42 corresponding to the multiple ridged upper surface 28 of thebearer bar. The extension 40 includes vertical side walls 44 arranged toabut the outer ends of the flanges 20 of the bearer bar.

Each lower portion 34 also constitutes a flange extending from the web30 and includes a lower edge or surface 46 arranged to engage the uppersurface 26 of an adjacent lower flange 22 of an adjacent bearer bar.Extending upwardly from each edge 46 is a locking surface 48. lnaddition, each lower flange portion 34 also includes an outer edge orsurface 50 arranged to engage the web of an adjacent bearer bar at aposition adjacent the lower flange thereof.

As noted above, each connector bar 12 is of substantially uniformcross-sectional configuration throughout its longitudinal extent and isbent transversely to provide the longitudinally extending bearer barengaging portions 14. In assembling adjacent bearer bars and connectorbars, the upper portion 32 of the longitudinally extending portions ofthe connector bar extending toward the assoelated bearer bar, arearranged to be inserted within the upper undercut flange 20 of theassociated bearer bar extending toward the connector bar. It will benoted, however, that since the transversely extending portions 16 of theconnector bar cross the undercut flange 20, the upper flange engagingportions of the longitudinally extending portion of the connector barcannot be inserted within the undercut flange. Therefore, in order topermit entry, either the flange of the bearer bar or the portion of theconnector bar at the junctures between the longitudinally extendingportions and transversely extending portions thereof must beinterrupted. As shown, the outer junctures between the longitudinallyextending portions 14 and transversely extending portions 16 of theconnector bar flange portions 32 are cut out as indicated at 52. Inaddition, to facilitate the transverse bending of the connector bar toform the reticulated configuration, the lower flange portions 34 are eutaway, as indicated at 54, at the outer junctures between thelongitudinally extending portions 14 and transversely extending portions16. The cutouts 54 are not essential, since the flange portions may bemoved into lateral engagement with the straight lower flanges 22 of thebearer bars without interference.

With the connector bars 12 cut away and bent in the manner indicatedabove, the grating is assembled by effecting a relative lateral andarcuate movement between a bearer bar 10 and a connector bar 12sufficient to initially insert the adjacent flange portion 32 within theadjacent undercut flange 20 of the bearer bar, as shown in FIGURE 4, andto subsequently move the surface 36 into registering engagement with thesurface 24 and the lower flange portion into engagement with the lowerflange of the bearer bar, as shown in FIGURE 5. It will be noted thatthe cutouts 52 enable the connector bar and bearer bar to be movedlongitudinally so that they can be properly positioned. Next, the outerend of the lower flange 22 is deformed upwardly, as indicated at 56,into engagement with the surface 48 to lock the two bars against lateralseparation. It will be noted that the upward bending of the lower flange22 deforms the metal such that it is disposed in the longitudinal pathof movement at the junctures between the longitudinally extendingportions 14 and transversely extending portions of the associated flangeportion 34 of the connector bar to thereby also prevent relativelongitudinal movement between the two bars. By this simple expedient,the two bars are rigidly interconnected with a minimum amount of timeand effort.

It Will be understood that the grating may be progressively built up, inthe manner indicated above, to any desired size. In this regard, it willbe noted that the bearer bars in the intermediate portion of the gratingcontact portions 14 of adjacent connector bars on both sides thereofand, preferably, the adjacent longitudinally extending portions 14 ofthe connector bars on both sides thereof contact the bearer bars at thesame longitudinal positions so that `both lower flanges 22 may bedeformed upwardly in one operation. This materially reduces the timerequired in assemblage.

It can thus be seen that there has been provided a grating assemblywhich may be readily constructed of individual bars of uniformcross-sectional configuration throughout their longitudinal extent. Thecross-sectional configuration of the bars is such that adjacent bars maybe interconnected by the simple expedient of effecting a relativelylateral and arcuate movement therebetween so as to initially insert afirst portion on one of the bars within a first undercut flange on theother bar and, subsequently, move the one portion and undercut flangeinto registering engagement and a spaced second portion on one of thebars and a spaced straight flange on the other bar into engagement.Where a reticulated connector bar is utilized, the undercut flangeengaging portion is cut away, which permits the two bars to be readilyadjusted longitudinally with respect to each other. Finally, the twobars are rigidly interconnected against both lateral and longitudinalmovement by deforming the straight flange over the portion engagedthereby.

It will be understood that the cross-sectional conguration of the barscan `be varied considerably from that shown without departing from theprinciples of the present invention. The essential feature is theprovision on one member of a pair of spaced flanges, one of which isundercut and one of which is straight, and the provision on thecooperating member of portions arranged to engage between the flanges byrelative lateral and arcuate movement so as to bring one portion intoregistering engagement with the undercut flange and the other portioninto initial contact with the straight flange so that the latter can besubsequently deformed thereover. The exact bar engaging surfaces of theflanges 20 and 22 are not limited to the straight dovetail surfacesshown.

It thus will be seen that the objects of this invention have been lfullyand eifectively accomplished. It will be realized, however, that theforegoing specific embodiment has been shown and described only for thepurpose of illustrating the principles of this invention and is subjectto extensive change without `departure from such principles. Therefore,this invention includes all modifications encompassed within the spiritand scope of the following claims.

I claim:

l. In a grating assembly having a plurality of straight bars andintermediate connector bars extending in the same longitudinal directionwith said straight bars substantially parallel, each straight bar havinga web and spaced pairs of opposite flanges extending laterallytherefrom, and each of one of said pair of flanges being provided withan undercut forming with said web an undercut opening toward the otherpair of flanges, and each connector bar having alternate oppositelylaterally displaced straight portions each provided with spaced pairs ofopposite outwardly diverging flanges adjacent and extending toward thestraight bar flanges, each of one pair of said outwardly divergingconnector bar flanges `snugly lockingly inter-fitting into correspondingundercuts of adjacent straight bar anges and the corresponding anges vofthe other pair of said straight bar anges being bent over the adjacentdiverging flange of said connector bar.

2. In a grating assembly having a plurality yof straight parallel barswith longitudinally extending intermediate connector bars between them,each straight bar having a web and spaced pairs of opposed flangesextending laterally therefrom and each connector bar being formed withalternate oppositely laterally displaced straight portions having a weband spaced pairs of opposed lateral flanges extending therefrom towardthe `adjacent straight bar flanges, the flanges of one of said barsdiverging from its web to form outwardly open recesses, and each of oneof the pairs of flanges of the other bar being provided with an undercutforming with the web of said other bar an inwardly open recessinterlocking with the corresponding `outwardly diverging flange orf saidone bar, and corresponding flanges of the other pair of flanges of saidother bar being 4bent over the other outwardly open diverging flange ofsaid one bar whereby to retain said bars in assembled interlockedrelationship7 3. In a grating assembly having a plurality of straightbars and intermediate laterally zig-zag connector bars extending in thesame longitudinal direction with said straight bars substantiallyparallel, each straight bar having a web and Ispaced pairs of opposedflanges extending laterally therefrom and each of one of said pair ofiianges being provided with an undercut forming with said web anundercut having an inclined surface and each connector bar havingalternate oppositely laterally displaced straight portions each providedwith spaced pairs of diverging flanges adjacent and extending toward thestraight bar anges, each of one pair of said outwardly diverging flangesinter-fitting with a corresponding said undercut surface andsubstantially conforming in angularity with said surface, andcorresponding flanges of the other pair of flanges of said straight barbeing crimped over the other adjacent diverging anges of said `c011-nector bar to hold said straight bars and said connector bars rigidlyinterlocked.

4. In a grating assembly having a plurality of straight bars andintermediate laterally zig-zag connector bars extending in the samelongitudinal direction with said straight bars substantially parallel,each straight bar having a web and spaced pairs of flanges extendinglaterally therefrom and each of one of said pair of anges being providedwith an undercut forming with said web an undercut opening toward the`other pair of flanges and each connector bar having alternateoppositely laterally displaced straight portions each provided withspaced pairs of outwardly extending flanges adjacent land extendingtoward the straight bar flanges forming outwardly extending undercutsopening away from each other, each of one pair of said outwardlyextending anges `of said connector bar snugly lockingly interftting withya corresponding inwardly opening undercut surface of straight bar angeand corresponding anges of the other pair of anges of said straight barbeing bent over the other out-A wardly extending ange of said connectorbar.

References Cited in the lile of this patent UNITED STATES PATENTS727,234 Walker May 5, 1903 1,344,882 Goldie June 29, 1920 1,865,059Ragsdale Iune 28, 1932 2,302,586 Thalen Nav. 17 194g

